Non-blocking drop-in replacement for read() function

[RedshiftVelocities]

The read() function now no longer locks up the Arduino for 40ms. It can be run every main loop, but only communicates with the sensor within the timing spec in the datasheet. The example sketch has also been updated to demonstrate this. These changes are a drop-in replacement for the existing read() function.

Note that I haven't been able to test the code on a real sensor; I've just used another Arduino pretending to be one.